Dianhydride compounds and polyimide films

Abstract

The present invention provides dianhydride compounds and polyimide films. The structural formula of the dianhydride compound is shown in formula (1). The present invention also provides a polyimide film prepared from an aromatic dianhydride compound and an aromatic diamine compound as raw materials, wherein the aromatic dianhydride compound includes the dianhydride compound shown in formula (1). The polyimide film prepared from the dianhydride compound of the present invention has a low thermal expansion coefficient, a high glass transition temperature, and excellent mechanical properties, and has better application prospects in fields such as flexible OLED displays.

Description

Technical Field

[0001] The present invention relates to a dianhydride compound and a preparation method thereof, and a polyimide film prepared by using the dianhydride compound. Background Art

[0002] Polyimide (PI) is a class of polymer compounds with imide rings in its backbone. In recent years, PI has gained widespread application in the microelectronics industry due to its excellent heat resistance, chemical stability, and mechanical strength. During the electronic component manufacturing process, PI films are often bonded or laminated to other metals or inorganic materials, such as copper foil, silicon wafers, and optical glass. These films withstand demanding high-temperature preparation conditions and multiple high- and low-temperature cycles. To ensure the quality of optoelectronic devices, flexible PI substrates must possess excellent heat resistance, flexibility, and dimensional stability.

[0003] Specifically, polyimide used in flexible OLED substrates has the following requirements: (1) high heat resistance. The PI substrate needs to withstand the high temperature (300-500°C) of the low-temperature polycrystalline silicon thin-film transistor (LTPS TFT) processing process. The higher the processing temperature, the more complete the polysilicon crystallization and the better the TFT performance. At the same time, thermal decomposition should be avoided to contaminate the device. (2) low coefficient of thermal expansion (CTE). The PI substrate needs to match the CTE value of the inorganic layer and metal layer in the device to reduce delamination and curling during processing.

[0004] Therefore, it is necessary to develop new polyimide films with low thermal expansion coefficient, high glass transition temperature and excellent mechanical properties. Summary of the Invention

[0005] In response to the above-mentioned technical problems, the present invention provides a dianhydride compound for synthesizing a polyimide film. The polyimide film prepared thereby has a low thermal expansion coefficient, a high glass transition temperature and excellent mechanical properties.

[0006] In a first aspect, the present invention provides a dianhydride compound represented by formula (1):

[0007]

[0008] wherein Ar1 is selected from C6-C 20 a substituted or unsubstituted aryl group;

[0009] Substituted aryl means that the H on at least one carbon atom of the aryl group is independently replaced by deuterium, halogen, cyano, C1-C 12 Straight-chain or branched alkyl, halogen-substituted C1-C 12 Substituted with straight-chain or branched alkyl, phenyl, or naphthyl;

[0010] Preferably, Ar1 is selected from substituted or unsubstituted phenyl, naphthyl, and biphenyl, wherein the substituents are each independently at least one of cyano, fluorine, trifluoromethyl, naphthyl, and phenyl.

[0011] Specifically, the dianhydride compound is any one of the following compounds:

[0012]

[0013]

[0014] The present application also provides an intermediate for synthesizing the compound represented by formula (1), which has the structure represented by formula (1-1):

[0015]

[0016] wherein X is selected from F, Cl, Br, and I;

[0017] Ar1 is as defined above.

[0018] The present invention also provides a method for preparing the dianhydride compound represented by formula (1).

[0019] The preparation method of the dianhydride compound represented by formula (1) provided by the present invention comprises the following steps:

[0020] 1) making the compound and compounds Perform Suzuki coupling reaction to obtain intermediate (1-1);

[0021] 2) The intermediate (1-1) undergoes self-coupling to obtain the dianhydride compound represented by formula (1).

[0022] wherein X and Ar1 are as defined above.

[0023] A second aspect of the present invention provides a polyimide film.

[0024] The polyimide film is prepared from an aromatic dianhydride compound and an aromatic diamine compound as raw materials, wherein the aromatic dianhydride compound includes the dianhydride compound represented by the above formula (1).

[0025] The polyimide film provided by the present invention is prepared by a method comprising the following steps:

[0026] 1) reacting an aromatic dianhydride compound with an aromatic diamine compound in an organic solvent to obtain a polyamic acid solution; the aromatic dianhydride compound includes the dianhydride compound represented by the above formula (1);

[0027] 2) Casting the obtained polyamic acid solution into a film, and sequentially performing drying, imidization and curing to obtain a polyimide film.

[0028] In step 1), the aromatic diamine compound is selected from the compound represented by formula (2):

[0029] H2N-Ar-NH2

[0030] Formula (2)

[0031] wherein Ar is selected from substituted or unsubstituted C6-C 30 Arylene, substituted or unsubstituted C5-C 30 heteroarylene;

[0032] Substituted C6-C 30 Arylene, C5-C 30 The substituents in the heteroarylene group are C6-C 30 Arylene, C5-C 30 At least one hydrogen on a carbon atom of the heteroarylene group is selected from deuterium, C1-C 12 Alkyl, C1-C 12 Alkoxy, C6-C 20 It is substituted by aromatic hydrocarbon groups, halogens, or cyano groups;

[0033] In one embodiment, the C6-C 30 The arylene group is selected from one or a combination of two of phenylene, naphthylene, anthrylene, phenanthrenyl, 9,9-dimethylfluorenyl, triphenylene, and fluoranthenylene;

[0034] In one embodiment, the C5-C 30 The heteroarylene group is selected from one or a combination of two of pyridylene, pyrimidylene, carbazolylene, N-phenylcarbazolylene, dibenzofuranylene and dibenzothiophenylene.

[0035] In one embodiment, the compound represented by formula (2) is selected from at least one of the compounds represented by the following structural formulas:

[0036]

[0037]

[0038] In one embodiment, the compound represented by formula (2) is selected from at least one of the compounds represented by the following structural formulas:

[0039]

[0040] The organic solvent is selected from the group consisting of: ethyl acetate, DMF (N,N-dimethylformamide), DME (N,N-dimethylacetamide), DMSO (dimethyl sulfoxide), HMPA (hexamethylphosphoramide), or a mixture of two or more thereof.

[0041] The molar ratio of the aromatic dianhydride compound to the aromatic diamine compound is 0.8:1 to 1:0.8, preferably 1:1;

[0042] The reaction temperature is -20 to 80°C and the reaction time is 3 to 48 hours. Preferably, the reaction temperature is 20 to 50°C and the reaction time is 6 to 18 hours.

[0043] The drying comprises drying at 150-200° C. for 1-12 hours.

[0044] Preferably, the imidization is carried out at 260-320° C. for 0.5-5 h.

[0045] Preferably, the curing refers to curing at 340-400° C. for 0.5-3 h.

[0046] The polyimide film has a low thermal expansion coefficient, a high glass transition temperature and excellent mechanical properties.

[0047] The application of the above-mentioned polyimide film in the field of flexible OLED display also falls within the scope of protection of the present invention; specifically, it can be the application of the polyimide film in the preparation of flexible OLED display substrates.

[0048] The beneficial effects of the present invention are:

[0049] The present invention provides a dianhydride compound with a novel structure and a polyimide film prepared using the dianhydride compound, in particular an aromatic dianhydride compound containing halogen (F), trifluoromethyl, and cyano groups. The polyimide film prepared from the aromatic dianhydride compound containing halogen (F), trifluoromethyl, and cyano groups has a low thermal expansion coefficient, a high glass transition temperature, and excellent mechanical properties, and has better application prospects in fields such as flexible OLED displays. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0051] Example 1 Synthesis of Compound P1

[0052]

[0053] (1) Synthesis of intermediate M1

[0054] Add 3.03 g into the three-necked flask 1.3 g of phenylboric acid, 50 ml of DMF, 4.0 g of anhydrous potassium phosphate, 0.2 g of tetrakistriphenylphosphine palladium, heated to 90 ° C for 8 hours, cooled, added to water, filtered the obtained solid, washed with cold water until neutral, dried, and crystallized with a mixed solvent of ethyl acetate and toluene to obtain 12.5 g of intermediate M.

[0055] The mass spectrum of M1 was measured, m / z: 301.96.

[0056] (2) Synthesis of compound P1:

[0057] In an autoclave, 2.5 g of intermediate M1, 0.7 g of anhydrous nickel chloride, 1.2 g of triphenylphosphine, 0.5 g (0.15 mol) of zinc powder, and 30 ml of tetrahydrofuran were added. After nitrogen substitution, the reaction was carried out at 80°C for 8 hours. The temperature was lowered, and the solid was removed by filtration. The mother liquor was concentrated to dryness and then crystallized from a mixed solvent of tetrahydrofuran and petroleum ether to obtain 11.1 g of product P1.

[0058] The mass spectrum of P1 was measured, m / z: 446.08.

[0059] The H spectrum of P1 was measured, and the data were as follows: (D6-DMSO was used as solvent), δ8.49 (s, 4H), δ7.53~7.40 (m, 10H).

[0060] Example 2 Synthesis of Compound P2

[0061]

[0062] (1) Synthesis of intermediate M2

[0063] Intermediate M2 was prepared by referring to the synthetic method of intermediate M1.

[0064] The mass spectrum of M2 was measured, m / z: 351.97.

[0065] (2) Synthesis of compound P2

[0066] Compound P2 was prepared by referring to the synthetic method of compound P1.

[0067] The mass spectrum of compound P2 was measured, m / z: 546.11.

[0068] Example 3 Synthesis of Compound P3

[0069]

[0070] (1) Synthesis of intermediate M3

[0071] Intermediate M3 was prepared by referring to the synthetic method of intermediate M1.

[0072] The mass spectrum of M3 was measured, m / z: 377.99.

[0073] (2) Synthesis of compound P3

[0074] Compound P3 was prepared by referring to the synthetic method of compound P1.

[0075] The mass spectrum of compound P3 was measured, m / z: 598.14.

[0076] Example 4 Synthesis of Compound P4

[0077]

[0078] (1) Synthesis of intermediate M4

[0079] Intermediate M4 was prepared by referring to the synthetic method of intermediate M1.

[0080] The mass spectrum of M4 was measured, m / z: 377.99.

[0081] (2) Synthesis of compound P4

[0082] Compound P4 was prepared by referring to the synthetic method of compound P1.

[0083] The mass spectrum of compound P4 was measured, m / z: 598.14.

[0084] Example 5 Synthesis of Compound P5

[0085]

[0086]

[0087] (1) Synthesis of intermediate M5

[0088] Intermediate M5 was prepared by referring to the synthetic method of intermediate M1.

[0089] The mass spectrum of M5 was measured, m / z: 326.95.

[0090] (2) Synthesis of compound P5

[0091] Compound P5 was prepared by referring to the synthetic method of compound P1.

[0092] The mass spectrum of compound P5 was measured, m / z: 496.07.

[0093] Example 6 Synthesis of Compound P6

[0094]

[0095] (1) Synthesis of intermediate M5

[0096] Intermediate M6 was prepared by referring to the synthetic method of intermediate M1.

[0097] The mass spectrum of M6 was measured, m / z: 358.02.

[0098] (2) Synthesis of compound P6

[0099] Compound P5 was prepared by referring to the synthetic method of compound P1.

[0100] The mass spectrum of compound P6 was measured, m / z: 558.20.

[0101] Other compounds were prepared according to the above method.

[0102] Example 7 Preparation of polyimide film

[0103] 500 ml three-necked flask, nitrogen protection, mechanical stirring, add 0.01 mol of compound P1, 0.01 mol of compound P, and 80 ml of DMF (N,N-dimethylformamide) were reacted at 25°C for 12 hours to obtain a light yellow polyamic acid solution; the obtained polyamic acid solution was coated on a glass plate and cast into a film, dried at 180°C for 8 hours, then imidized at 300°C for 2 hours, and cured at 360°C for 1 hour to obtain a polyimide film.

[0104] The performance test of the polyimide film prepared in Example 7 showed that the glass transition temperature Tg was 276° C. and the coefficient of thermal expansion CTE was 39.1 ppm / K.

[0105] The glass transition temperature Tg of the obtained polyimide film was tested by using a Q800DMA instrument from TA Company of the United States in a tensile mode for analysis.

[0106] Examples 8-14

[0107] Referring to the method of Example 7, the following polyimide films were prepared, except that the raw materials were different, as shown in the table below:

[0108]

[0109]

[0110]

[0111] The data in the table show that, compared to the prior art compound DP1, the polyimide films produced from the dianhydride compounds of the present invention have higher glass transition temperatures and lower coefficients of thermal expansion. In particular, the polyimide films produced from compounds P5, P7, and P8 have lower coefficients of thermal expansion (CTE).

[0112] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A dianhydride compound, characterized in that The structural formula of the dianhydride compound is shown in formula (1): wherein Ar1 is selected from substituted or unsubstituted phenyl, naphthyl, biphenyl; Substituted phenyl, naphthyl, biphenyl refers to phenyl, naphthyl, biphenyl at least one of the carbon atoms of the hydrogen is independently replaced by deuterium, halogen, cyano, C1-C 12 Straight-chain or branched alkyl, halogen-substituted C1-C 12 Substituted with straight-chain or branched alkyl, phenyl, or naphthyl.

2. The dianhydride compound according to claim 1, wherein The substituents are each independently at least one of cyano, fluorine, trifluoromethyl, naphthyl, and phenyl.

3. The dianhydride compound according to claim 1 or 2, wherein The dianhydride compound is any one of the following compounds:

4. The method for preparing the dianhydride compound according to any one of claims 1 to 3, comprising the steps of: 1) making the compound and compounds Perform Suzuki coupling reaction to obtain intermediate (1-1); Ar1 is defined as Ar1 in claim 1 or 2; 2) The intermediate (1-1) undergoes self-coupling to obtain the dianhydride compound represented by formula (1).

5. A polyimide film prepared from an aromatic dianhydride compound and an aromatic diamine compound as raw materials, wherein: The aromatic dianhydride compound includes the dianhydride compound according to any one of claims 1 to 3, and the aromatic diamine compound is 6. A method for preparing the polyimide film according to claim 5, comprising the steps of: 1) reacting an aromatic dianhydride compound with an aromatic diamine compound in an organic solvent to obtain a polyamic acid solution; the aromatic dianhydride compound comprises the dianhydride compound according to any one of claims 1 to 3; 2) Casting the obtained polyamic acid solution into a film, and sequentially performing drying, imidization and curing to obtain a polyimide film.

7. The method according to claim 6, wherein: The molar ratio of the aromatic dianhydride compound to the aromatic diamine compound is 0.8:1 to 1:0.8; the reaction temperature is -20 to 80°C, and the reaction time is 3 to 48 hours; the imidization is carried out at 260 to 320°C for 0.5 to 5 hours; and the curing is carried out at 340 to 400°C for 0.5 to 3 hours.

8. Use of the polyimide film according to claim 5 in the field of flexible OLED displays.

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